Games: 4x4 EVO2

You can almost see the secret smile cross the face of 4x4 owners as they reach the end of the asphalt. They know they can take their trucks or Sport Utility Vehicles (SUV) where no other cars can go. They can plow up mountainsides, splash through gullies, and climb to the top of mesas. And while they know they can go practically anywhere, they also know that going off-road is the fastest way to rack up countless car repair bills. So they do the sensible thing and remain on the road. Well, it’s time to say goodbye to doing the sensible thing. With 4x4 Evolution 2 ™ all those dirt-covered racing desires can finally be fulfilled without scratching the bumper one little bit.

The original 4x4 Evolution was all about the battle between machine and mud, and the sequel takes this conflict to the next level. All the mud caked messiness that populates off-road racing has found its way into 4X4 EVO 2. The game puts you behind the wheel of real-world trucks and SUVs and lets you barrel over jaw-dropping environments such as the high desert, junkyards, military airbases, and an airplane graveyard. And you don’t have to worry about staying on the course. Each environment sports enough humps, trees, massive rocks, and car-swallowing mud bogs to keep you guessing where the finish line is.

4X4 EVO 2 improves upon the real-world dynamics and cutting edge graphics from the original game and adds a variety of new twists and turns such as an adaptive artificial intelligence system and a completely reworked physics model. Developer Terminal Reality leveraged the power of the next generation of new graphics hardware to add real time lighting and fog effects, real time terrain reflections, as well as mud textures that and bump mapped streams. 4X4 EVO 2 features lush, photo-realistic environments, high-resolution textures, and a fleet of masterfully detailed, high polygon SUVs and trucks.

Every popular truck and SUV you can think of is in this game, from the Dodge Durango to the Jeep Wrangler. The game’s hyper-accurate physics model takes into account each vehicle’s weight, equipment, and handling. So if you’ve ever wondered what your shiny new 4x4 could really do off-road, it’s time to fire up 4X4 EVO 2 and find out.

We talked to the development team at Terminal Reality to get the skinny on the next evolution in off-road racing.

What’s new in 4X4 EVO 2?We discovered that many people went off of the track, just driving around in original game. Unfortunately, the landscape in 4x4 Evolution was good, but there wasn't that much to see off the track. To correct this we populated the 4X4 EVO 2 world with over 30,000 trees and a million plus pieces of scrub. When you go off the track now you run across natural obstacles and feel like you’re really tearing through the actual terrain of a remote environment. Because these changes made the off-roading portion of the game so interesting, we came up with a "Free Roam" mode where there is no racing, no competitors, and no agenda. You just go driving around, exploring the lush environment and doing some "true off-roading".

We have new cars from new manufactures and we’ve introduced a huge variety of licensed third party manufactured parts to the career section of the game such as the Safari snorkel, the ARB bumper, and the Warren winch. The winch has turned out to be a very popular addition to the game, allowing players to get over those tough hills and difficult obstacles.

How many different environments are there in the game? How large is the average off-road map?4X4 EVO 2 boasts 32 unique environments, ranging from the swamps of Louisiana to the pyramids of Egypt. The maps are all 1.6 miles by 1.6 miles or approximately 70 million square feet. The size of the track varies, from a two-minute drive at top speed (one lap) to eight to ten minutes for a lap depending upon how good you are.

What were you able to do with 4X4 EVO 2’s game engine to take advantage of the latest technologies offered by GPU’s such as the GeForce3?The GeForce3’s pixel shaders allowed us to create real time reflections and gloss maps for vehicles and the fast stencil buffers are great when it comes to accurate shadows. We also were able to generate more realistic surfaces across water and tires for instance, by using dot product 3 bump mapping.

What effects were easier to implement using pixel and vertex shaders as opposed to standard techniques?Since we wrote our own lighting equations in 4X4 EVO 2, it’s much easier to have the vertex shader do them. For vehicles, we used our own “gloss” technique to make the trucks and SUVs reflect and get dirty, so we designed custom vertex and pixel shader routines to do this in one pass. Real time reflections are significantly easier thanks to the built in functions of the vertex and pixel shaders and texture projections, whether they are for lights or shadows, are significantly less CPU intensive on a GeForce3 because you can offload much of the work to the shader units.

The raw power of the GeForce3 allows you to push a lot of polygons without your computer coming to a screeching halt. What is the highest amount of polygons an end-user could see in a given scene?

4X4 EVO 2 can push about 200,000 polygons in a scene with all effects turned on.

With all the high quality models and detailed textures 4X4 EVO 2 is stunning. What are you doing to efficiently handle the incredible loads needed to feed these high polygon models and huge textures?

We do several different things to handle the heavy graphics loads in 4X4 EVO 2. First, we judiciously use one of our own custom texture compression algorithms to load one-third the amount of data on average. Once a level is loaded, all the textures are created in video memory and kept there so all the bandwidth goes to rendering. Finally the model geometry is batched and then cached to video memory after the textures get loaded.

Because you are offloading the Transform & Lighting, Vertex Shaders, and Pixel Shaders to the GPU, what have you done with the extra CPU cycles regarding the game’s physics and AI?For the physics we used the extra cycles to do per-polygon collision detection with most objects and detect collisions with the thousands of new trees. As far as AI, we try to evade collisions, adjust difficulty, and knock the player around a bit.

How realistic is the game’s physics model?The games physics are very realistic while at the same time not compromising gameplay. For example the physics model each suspension realistically, and the aerodynamics are accurately modeled, etc. Each vehicle has more than a hundred parameters defining its dynamics. Some things we do to make the game more fun to play is lower the center of gravity and increase the speed of the game. The gravity makes it a little harder to roll the vehicle and the increased speed makes the game play faster.

Tell us about 4X4 EVO 2’s adventure mode?The adventure mode is a way to step outside of the normal racing that was the primary focus of the original 4x4 Evolution.You take on these adventures in the game’s career mode to earn extra cash. They range from delivering supplies to a town cut off by an earthquake, to finding a crashed airplane and looking for survivors, to putting on your explorer hat and finding an ancient ruin. The environments are massive so you can spend hours and hours on each adventure.

4x4 Evolution was lauded for its innovative multiplayer, why did you choose to focus so much attention on the single player experience in the sequel?We did this because the Xbox launch was a big target we wanted to hit, we had to think about the PC player and the Xbox player. Xbox doesn't have an on-line solution right now, so we had to make sure that the single player component of EVO 2 was compelling enough that multiplayer wouldn't be missed (as much). Nothing beats getting on line and racing against real people, but we have done our best to make playing off line an extremely rewarding experience.